• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

DTV reception question ... 1,200 ft in elevation and no signals from 12 miles away?

gar hi

gar hi

Unlike radio and old analog TV, I'm not familiar with the dynamics of DTV reception.

In recent years, I've hardly watched any TV and when I moved out here, I didn't take my TV with me and I haven't had TV since I've been here.

But then after being at my neighbor's place (he gets DTV channels from Hilo over the air with an outdoor old fashioned UHF antenna 30 plus feet high), I've been longing for TV again.

I didn't want to spend a lot of money and I never cared for huge screen TVs, so I ordered from Amazon a 9 inch portable DTV. I like small electronics and it fits right next to my computer on my desk.

Here it is. It had mostly very good reviews too and it's a nice little solid TV.

http://www.amazon.com/SuperSonic-SC...784&sr=8-1-spell&keywords=9+inch+portable+dtv

So I got it today and I didn't expect to get much with the little antenna on the TV but I can't even get one channel from 12 miles away in Hilo even at 1,000 plus feet in elevation.

Now, there may be some terrain that blocks the line of sight path between here and Hilo but I'm surprised that I can't get anything. Also, I've never seen any real radio towers around Hilo, so I don't even know where the stations come from.

Then I called Radio Shack in Hilo and the person was very helpful after I explained my problem. She lead me to a website - AntennaWeb.org and asked me to put in my location. The results were 0 (zero) channels that could be received and she explained that meant using only an indoor antenna.

She said that I would need an outdoor antenna and it should be at least 30 feet above the ground. I'm 20 feet above the ground as it is and I could mount an antenna on the roof, I guess.

My first thought in all this was that maybe the TV was defective and I was ready to send it back but now that I've learned more, I'm wondering if it's worth going to the trouble to buy an antenna to put outside.

If I do decide to do that, I will take my TV into Hilo and run the channel scan there to make sure it's not just the TV. I certainly should be able to pick up the stations there without help with any attached external antenna.

But I'm still surprised that even without any external antenna that I couldn't get any channels where I am.

Any thoughts on this would be appreciated.
 
That, I know and it's one thing I don't like about digital TV.

When I was in Tampa, I was about 15 miles from the TV transmitters, had one of those flat square digital indoor antennas in my closet on my 1st floor apartment, and even those local stations would break up or go away completely during heavy rains, wind, and especially thunderstorms.

I would even sometimes get that blank picture that said 'no signal' during times of high winds and no rain.
 
It doesn't take much in the way of obstructions to make a digital television signal disappear, especially if AntennaWeb says nothing is receivable with an indoor antenna. You might have a couple of trees in just the wrong place on the line of sight to the transmitters, or something similar.

You're being very logical and methodical about this, though. Certainly, testing the TV in an area which should have strong reception is a logical next step.

Let us know what you discover.
 
Did you run a scan on it?
If there are any low-power analog stations in that vicinity (hopefully, on the same site as the digitals), try finding a spot where they come in best. Then, run a scan for the digital channels...they have to be "discovered" by the set, or it won't know how to find them.
Otherwise, you might have to try a scan in several different locations, near windows, or along the walls that face the stations' transmitters.
If all else fails, you'll need a better antenna, either a good indoor one, or a small outdoor one.
 
I've run channel scans many times and the results are '0 channels found' on both analog and digital.

But I tried to enter different channels by using the remote and on channel 4, I got an analog signal which is mostly 'snow' but there seems to be some very weak signal too. Don't know where that could be from.

When he gets a chance, my neighbor I mentioned with the outdoor antenna will let me connect my TV to it to see what I get.

In the mean time, someone told me about 'Clear TV Digital TV Antenna'. It's only $20 and looks like a thin piece of plastic but I've been looking at reviews on YouTube and most all are very encouraging. It has a 15 ft attachment chord, so I may be able to mount it outside too.

Here's one of the many positive reviews.

https://www.youtube.com/watch?v=V0lYz_gnasI
 
You should go to this website:

http://www.fccinfo.com/

Find the actual (not virtual) channel numbers of the TV stations which you are attempting to receive.

One by one, enter the actual channel number of the TV station followed by a .1 and adjust your antenna for the highest signal strength.

As has been posted ...... multipath that would produce a "ghost" in the analog TV world, will totally kill the reception of a digital TV signal.
 
Thanks!

I started entering call letters and I forgot that the channels in Hilo are repeaters of Honolulu stations that transmit locally.

One thing I don't get about DTV is why most use UHF frequencies.

I remember from my old analog DXing days how much worse the reception was on UHF than it was on VHF.

My brother even had a special UHF antenna back in the 60's that was only about a foot long and wide and looked like a mini version of one of those VHF roof antennas and even the local stations still had problems with ghost images.

No wonder DTV is harder to get than it should seem.
 
In the DTV era, VHF signals, especially those on channels 2 to 6, are considered worse than UHF. It has to do with the size of antennas that most households have. It is nearly impossible to receive VHF DTV on indoor rabbit ears unless you are very close to the tower site.
 
hawaiigar said:
One thing I don't get about DTV is why most use UHF frequencies.
Click to expand...

Because UHF antennas are smaller, have higher gain for a given size, and are much more directive. Directivity is of absolute importance for DTV -- as mentioned earlier, multipath is a signal-killer with digital, while it only created ghosts in analog.

And once the UHF band is cut down to Channels 14-36 (or whatever it ends up being), a super wide antenna bandwidth won't be necessary. Wider bandwidth requires a compromise that lowers gain.
 
hawaiigar said:
I remember from my old analog DXing days how much worse the reception was on UHF than it was on VHF.
Click to expand...
But VHF, especially low-band VHF, is and has always been much noisier than UHF.
 
ai4i said:
But VHF, especially low-band VHF, is and has always been much noisier than UHF.
Click to expand...

Very true. Static from lightning affects low-VHF like it does Ancient Modulation radio -- one crash and the picture goes bye-bye for a few seconds, where in the analog world, you'd just get blips on the screen..
 
I found out that two of the stations from Hilo have actual broadcast frequencies on the upper end of VHF - channels 11 and 13.

My favorite, MeTV, is on 13.3.

I guess if I get one of those typical small square DTV antennas, I will have problems getting those channels?
 
Well, I just connected my little TV to my neighbor's outdoor digital antenna, did a scan, and only got 3 channels. They were breaking up too.

Whereas his TV gets 14 channels. It is raining a lot, though.

I don't know if it's worth trying to get a good antenna or not and I really don't want to have to send the TV back to Amazon.
 
Well, that is odd. The neighbor's TV gets 14 channels and yours get only three poorly. I guess your 9 inch TV just doesn't have the sensitivity that a larger set with more features might have.

I'm not sure why you'd want a 9 inch TV. Small radios are fine, even Walkmans that you have to listen to with headphones. But I don't understand the concept of watching a TV program and missing most of the visuals.

It is harder to get reception with DTV. But once you get it, the picture is close to cable quality. My experience is that with the switch-over, I lost a couple of channels I used to get in analog. But I got so much better reception on the other channels, not to mention a range of subchannels, that I think the change is worth it. If you like Me-TV, subchannels like that wouldn't be possible with analog.
 
I'm not sure why you'd want a 9 inch TV. Small radios are fine, even Walkmans that you have to listen to with headphones. But I don't understand the concept of watching a TV program and missing most of the visuals.
Click to expand...

It all depends on what you're used to. Most have been conditioned to think you need the biggest screen possible and those who sell such thing$ love that.

Again, I'm not much of a TV person and the last one I had was only a 20 inch. That was fine with me.

There's no room for even that sized TV where in am now and it's OK because I'm used to watching movies on Netflix on my laptop which sits on my desk and the 9 inch TV fits just right next to it.

To me, sitting a foot or two away from a small screen is the same as sitting six to ten feet away from a large screen.

My focus now is getting the right antenna and if I still don't get the reception I want, I can just return the antenna.
 
OK, I work at a TV station (actually three) in Nashville, TN. First you MUST scan the airwaves to see what you can pick up. Just because the station identifies itself as Channel 5 does not mean it is actually broadcasting on channel 5 (well, actually in Nashville it is, along with a UHF channel, too). Where I work, 17 is actually on UHF 15, 58 is on UHF 21 and I forget where 30 is. The old channel numbers are just labels now. Once your TV has scanned your area those labels are applied to the actual channel, or frequency, so when you press 4 and hit enter on your remote, the TV goes to the frequency that labeled 4, not the actual frequency assigned to channel 4.
About the signal being either off or on: The RF signal is always on. Your TV must receive an RF signal strong enough to decode the digitally encoded information and display a picture and sound. If the RF signal is too low, no picture, but there is still an RF signal.
The FCC wants to use the VHF channels for commercial and industrial usage, whatever can be transmitted over an RF signal.
 
As I said earlier, I scanned many times and the scan goes by the RF numbers and yes, I know the listed frequency and actual frequency (RF) are different.

Can't wait to see how the 'Clear TV' antenna works, if it's as good as the YouTube reviews say it is, when I get a chance to go down to Hilo and get one.

If that doesn't any or enough channels, I'm returning that and sending the TV back to Amazon. Such a nice little TV as far as appearance goes and I hope I don't have to part with it.
 
hawaiigar said:
Well, I just connected my little TV to my neighbor's outdoor digital antenna, did a scan, and only got 3 channels. They were breaking up too.

Whereas his TV gets 14 channels. It is raining a lot, though.

I don't know if it's worth trying to get a good antenna or not and I really don't want to have to send the TV back to Amazon.
Click to expand...

Take that as a hint: Your 9 inch TV has a deaf tuner. Send it back.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom